Autistic traits are widely thought to operate along a continuum. A taxometric analysis of Adult Autism Spectrum Quotient data was conducted to test this assumption, finding little support but identifying a high severity taxon. To understand this further, latent class and latent profile models were estimated that indicated the presence of six distinct subtypes: one with little probability of endorsing any autistic traits, one engaging in ?systemising? behaviours, three groups endorsing multiple components of Wing and Gould?s autistic triad, and a group similar in size and profile?to the taxon previously identified. These analyses suggest the AQ (and potentially by extension autistic traits) have a categorical structure. These findings have important implications for the analysis and interpretation of AQ data. Electronic supplementary material The online version of this article (doi:10.1007/s10803-016-2897-z) contains supplementary material, which is available to authorized users.

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